Chusetts



A, D. ABBENZELLER.

SICKLE BAR.

APFLICATIQN FILED JAN-29.1917.

Patented June 10, 1919.

. j B/W, a T'Hfiy,

plan view of the'same, but

UNITED STATES PATENT OFFICE.

ALFRED 1). ABBENZELLER, or mnnoLrH, MASSACHUSETTS, ASSIGNOR 'ro UNIVERSAL SICKLE BAR GOMPANY,.OF'IBOSTO1\T, MASSACHUSETTS, A CORPORATION or MASSA- CHUSETTS.

V SICKLE-BAR.

Specification of Letters Patent.

Patented J line 10, 1919.

Application filed January 29, 1917. SeriaLNo. 145,315.

To all whom it may concern:

Be it known that I, ALFRED D. ABBEN- ZELLER, a citizen of the United States, and a resident of Randolph, in the county of Norfolk and Commonwealth of Massachusetts, have invented certain new and useful Improvements in Sickle-Bars, of which the following is a specification. f i

y The purpose of this invention is the construction of improved means for attaching the blades or cutters to a sickle bar such as is used in mowing machines, harvesters and the like; the fastening means being designed to secure the blades to the bar with absolute rigidity and certainty, while permitting their removal and replacement with ease and quickness. 1

To this end, my invention consists essentially'in forming each blade with a dovetail shank slidably entering a slot in the bar and held therein by a block which requires a suitable amount of force for its withdrawal.

Referring to the drawings forming part of this specification, Fi ure 1 -is' a plan view of a section of a sickle ar showing parts of a plurality of blades fastened therein. Fig. 2is an edge view of the same. Fig. 3 is a 7 M with apart broken away, and showing one of the blades having its locking block partially removed. Fig. 'tis a cross section of the bar and of a partially withdrawn locking block. Fig. 5 is a cross section at XX inFig l. Each blade or cutter 1 is of well known form, with the eliceptionthat its shank 2 is slightly dovetailed, as shown in Fig. 3. The sickle bar 3 ,is formed with as many slots 4 as there are blades, each slot being parallel with the top surface of the bar, slightly wider than the thickness of the shanks, and nearly half an inch longer.

The ends of the slots are substantially parallel with corresponding edges of the shanks, except at one end, as at 5, the slotend and the adjacent edge of-the shank being out of parallel, with their ends next the blade slightly nearer together to fit the wedged shape of a locking block 6. The shanks being narrowed than their slots 4, the former can be freely inserted in the slots, but after the locking blocks or wedges 6 have been driven into the spaces between the shanks and the slot-ends, no force can disturb the blades.

would-not be held -To prevent the wedges 6 from being accidentally jarred out, each is formed with one or more ribs 7 positioned to engage depressions or grooves 9 formed in the upper or under surfaces of the associated slot, or in both.. The portion of the sickle bar forming the top or roof of the slots is made comparatively thin and resilient to permit the ribbed wedges to be driven into place, but the resistance to withdrawal to be sufficient to require a special tool to pull the wedges out.

For such a tool,I prefer to employ a lever 10 having an oblique end 11 with a pin 12 at the obtuse corner 13; The wedges being each formed with an eye 1 1 in their outstanding section, when the pin of the tool is inserted in the eye of a wedge and the tool handle forced to one side upon the corner 16 as a fulcrum, such wedge is extracted with comparative ease. The same tool can be made ,to serve 'as a hammer for driving the wedges into place.

It is not absolutely necessary to have the blocks 6"given alwedged shape, inasmuch as they would look the shanks in place even if their edges were parallel; but while the blades would be kept from falling out, they with the same firmness and rigidity as is given them by the wedging action.

I prefer to make the sickle bar by spotwelding two strips 20, 21 and a suitable number of sections 22, together into one practically-integral whole. Thls 1s much 'more durable as well asless'ex'pensive than riveting the parts together, or otherwise formingthe bar. I

A bar thus constructed is appreciably stronger than one in which the blades are riveted to the bar, not only because the rivetholes weaken it, but because of the cellular structure thereof.

In the manufacture of this sickle bar, the bar itself is first formed, and the blades and locking blocks having been stamped out and the blades suitably sharpened, it is the work of but two or three minutes to insert the blade-shanks into the slots and to drive the locking blocks in with but a blow or two of a hammer on each.

If a blade gets dented or bent by impact with a stick or stone, it takes but a moment to remove it and replace it with another kept on hand for the purpose. When the blades become dull, they can be taken out,

sharpened and returned in a comparatively short time.

In order to demonstrate how much stronger is this method of attaching the blades in comparison with riveting them to thebar, I applied a tensional strain to the point of a blade parallel with the bar, in

both types, and found that my block-fas tcned blade withstood a strain several times greater than was needed to cause the shearing off of one of the rivets of the old style of sickle bar.

Another very important feature of this sickle bar is that by means of which the blades are adapted to add to the strength of the bar in resisting bending strains. In aclatter are gripped between the lips of the groove 23.

Another advantage derived from this retreating of the cutting edges of the blades within the groove, is that there can be no catching of the grass, strings or cloth between the edges of the blades and the face of the bar; the edges to which I refer being those of the shoulders 24:.

What I claim as my invention is:

1. A sickle bar having thin transversely disposed slots through it, blades each having a dovetail shank in each of the slots, one edge of each shank being spaced from an end of its associated slot, and a removable block filling the space thus left in each slot, each block being of substantially the same thickness as the blades and lying in the same plane, and having means for preventing its accidental displacement.

'2. A sickle bar having thin transversely disposed slots through it, blades each having a dovetail shank in each of the slots, one

edge 'of each shank being spaced from an end of its associated slot, and a block filling the space thus left in each slot,-the blocks being of substantially the same thickness as the blades and lying in the sameplane, but

slightly wider at their outer ends than at their inner ends and having resiliently 0peratlve means for preventlng their accidental displacement.

being formed with a projection and each .slot havlng a depresslon receiving the projection and acting to prevent the blocks too easy displacement. 1

a l. A sickle bar having thin longitudinally disposed slots extending, transversely through it, blades'each halving a dovetail shank in each of the slots, an edge of each shank being spaced from-an. end of its as sociated slot, and a block filling the space thus left in each. slot, each block having means to resist removal and having a'port1on normally exterior to the bar, saidportion having "a hole therein, whereby 'a lever arm having a pin adapted toenter said ,hole

can be used foriforcing each block out, from its slot. Y.

5. A sickle bar having longitudinally .extending slots through it and agroove in line with the slots, and blades having shanks.

confined-insaid slots, saidshanks being narrower, than the bases of the blades, and forcibly removable blocks filling thespaces between the shanks and their respective slots andlocking theblades in place, the basesiof the blades fitting in said groove and the.

junctures of the cutting edges of the blades being overhung by the. edges of said groove. In testimony thatI claim the foregoing invention, .1 have hereunto set my hand-this 25th day .ofJ anuary,1917 ALFRED n. ABBENZELLER.

Copies of this patent may be obtainedfor five cents each, by addressing the Commissioner of Patents,

Washington, D. .Q. r r 

